Microsoft has halted distribution of its Windows 7 USB/DVD Download tool after questions were raised as to whether the software utility makes improper use of open-source code. The tool is designed to help owners of Windows XP-based Netbooks get Windows 7 onto their machines.Photo by Microsoft

Microsoft has halted distribution of a tool aimed at making it easier to put Windows 7 on Netbooks amid allegations that the utility makes improper use of open-source code.

The software maker said on Tuesday that it has pulled down the Windows USB/DVD Tool while it investigates the issue, which was raised last week by Windows blogger Rafael Rivera on his Within Windows blog.

In his blog post, Rivera said Microsoft appears to use code from a tool called ImageMaster that is licensed under the GPLv2 open-source license. The General Public License, like other open-source licenses, allows code to be freely used by others, but has its own set of terms and conditions, such as sharing any modifications made to the code.

Microsoft confirmed it has launched a review of the matter and taken the utility off its online Microsoft Store until that inquiry has been completed.

"Microsoft is looking into this issue and is taking down the (Windows 7 updating) tool from the Microsoft Store site until its review is complete," the company said in a statement. "We apologize to our customers for any inconvenience."

Though somewhat arcane, the utility is important because it solves a technical challenge in upgrading the operating system on Netbooks and other PCs without an optical drive.

The issue is also a thorn in Microsoft's efforts to show that it can play nice with the open-source community. As ZDNet blogger Mary Jo Foley notes, this isn't the first time Microsoft has been accused of misusing GPL code.

Microsoft has also released a number of products under various open-source licenses itself, though typically not under the GPL, which it sees as one of the more restrictive licenses. Redmond has been particularly critical of terms in version 3 of the GPL.

Microsoft has taken a number of different approaches to open-source software, particularly Linux. The software maker has at times accepted the notion of a heterogeneous world where Linux and Windows co-exist, pledging to do better to make sure IT administrators can manage mixed environments.